Hi my name is ***** ***** I will be the expert working with you today to help and resolve the problem you have posted.
Remove the new lens and try to put the old lens back and let me know if you get the display fine on the viewfinder?
I am having a frequent internet outage so i will let this question open to other experts input. you will get an email notification as soon as an expert responds.
Hi. My name is*****'m a camera repair technician with almost 30 years in the business and I'll be glad to help you with your question today.
Do you turn the power off when you changed lenses?
The problem would seem to be electronic in nature and is going to require disassembling the camera to troubleshoot and repair by an experienced camera repairman. You may want to check locally for a camera repair shop in your area, or, if you need assistance finding a shop, please let me know and I'll locate one for you.